This is an application for continuation funding through the P50 Center mechanism, of a productive multifaceted clinical research program on drug abuse that is currently supported through NIDA's R18 Treatment Research Unit/Demonstration mechanism. The application proposes to establish a Behavior Therapy Treatment Research Center at the Behavioral Pharmacology Research Unit of Johns Hopkins University/Key Medical Center. The Center will emphasize a consistent theme which is development and evaluation of incentive therapies for the treatment of substance abuse. This emphasis builds on a long and productive history of the research group in pioneering contingency management research with substance abusers. The proposed research also builds on significant recent developments in the field which have demonstrated the potency of incentive therapies for promoting drug abstinence of outpatient treatment samples. The proposed research will extend current knowledge about the use of incentive therapies while obtaining important information on both mechanisms and practical application of these approaches. The Center consists of five components. The Core provides essential central shared resources to all other components; these include psychiatric assessment, computer, statistical, subject recruiting, secretarial and administrative support services. Component 1 will systematically explore parameters of methadone take-home incentives for intravenous polydrug abusers previously shown effective for improving treatment outcomes in methadone patients. Component 2 will conduct controlled evaluations of promising new voucher incentive therapies for intravenous polydrug abusers in which retail goods and services are made available contingent on cessation of on-going drug abuse during methadone treatment. Component 3 will explore voucher incentive therapies for cigarette smokers designed to prevent relapse and improve smoking cessation outcomes by rewarding continuous post-cessation smoking abstinence. Finally, Component 4 will conduct controlled evaluations of voucher incentive therapies for pregnant drug abusing women enrolled in treatment at the Center for Addiction and Pregnancy (CAP) that target program attendance and participation as well as reduced drug use in order to improve both maternal and fetal outcomes. Overall, these components represent a coordinated research effort that will provide systematic information about the mechanisms and effectiveness of incentive therapies for treatment of substance abuse. Valuable information will be obtained about the optimal conditions for applying these interventions as well as their utility across several specific populations of drug abusers.